Environment, Government, Green Design, Sustainability, Water
Back to Basics: Improving our Cities with Natural Systems
An Interview with Dwayne Myers
Dwayne Myers is a senior water resources engineer based at CDM Smith’s Neysadurai Centre in Singapore. His experience includes long-term sustainability of urban water resources, low-impact development and green infrastructure technologies, hydrology and hydraulics, combined sewer and stormwater management, surface water quality and comprehensive watershed management.
What is green infrastructure?
Green infrastructure is a broad concept that considers the benefits of natural systems, as opposed to manmade infrastructure, in land use planning. Natural systems can perform many functions, sometimes more efficiently than built systems. Absorbing and recycling wastes and pollutants, purifying air and water, and cycling carbon and nutrients are some examples.
My experience relates specifically to using natural processes—soil, water and plants—to manage rainwater. The idea is to treat rainwater as a resource, rather than a drainage problem. Through the use of techniques, such as decentralized systems, sidewalk planters, rain gardens, porous pavement and green rooftops, water is reused near the source, reducing pollution of surface water and improving the function of landscapes.
Does implementing green infrastructure produce tangible benefits?
Absolutely. Natural systems improve water quality, reduce ecosystem damage, prevent flooding and create a cooling effect. Lowering urban temperatures reduces energy use and has a direct human and environmental health benefit through the direct absorption of greenhouse gases and air pollutants. Green space also creates opportunities for active recreation and passive enjoyment.
In addition, real estate data indicates that intangible benefits are significant. By comparing home prices in two neighborhoods that are similar in every way other than greenery, we see that people want to live in green neighborhoods.
What challenges do cities face when considering green infrastructure?
The main challenges are not technical. Designing and building rain gardens and green roofs are relatively easy compared to other structures, like tall buildings and wastewater treatment plants. Also, public support is generally not an issue—most people support greener communities.
The primary obstacle is that established cities have made huge investments in infrastructure systems, and have strong institutions, laws and policies—formal and informal—that are responsible for maintaining and operating the systems as they exist. Any major change is often perceived as risky.
Also, there are multiple utilities and public agencies responsible for different components of the urban system, including wastewater and stormwater infrastructure; transportation; parks, recreation and open space; and private land use. Retrofitting an established city with green infrastructure requires coordination among these entities.
How can cities overcome these challenges?
Cities can take advantage of small changes. As they implement other projects, such as repaving streets and redeveloping waterfront areas, they can slowly start to incorporate green infrastructure practices. Development sites and buildings are constantly coming and going—these are opportunities to create more sustainable systems.
Strong leadership and a culture willing to experiment will facilitate change. An external driver, such as a technological breakthrough or a crisis, could influence a movement toward green infrastructure, but leadership is still imperative.
Are there economic benefits that balance the initial capital investment when retrofitting a city with green infrastructure?
Quantifying benefits of ecosystem services is an entire field of research and debate. Our studies suggest that life-cycle costs of green infrastructure are typically in line with those of traditional infrastructure in urban areas. However, when you consider factors that are difficult to quantify—ecosystem and human health, water quality and climate change impacts—we find that the magnitude of benefits is greater than the costs. We are also creating jobs using different types of skills and labor, employing a greater number of people.
Do you see a significant trend toward sustainable land development practices, or is this a new concept?
Green practices are common in Western Europe and Japan, where technology and institutional knowledge have been driving change for decades. In parts of Tokyo, there is wide use of porous pavement, allowing rainwater to trickle to networks of distribution pipes, to manage flooding.
A few American cities are implementing larger-scale programs, such as Seattle, Washington; Portland, Oregon; Chicago, Illinois; and Philadelphia, Pennsylvania. I expect that more cities will follow at different paces, with motivating factors, such
as rising energy and fuel prices.
What type of work are you doing at CDM Smith's Neysadurai Centre for Integrated Water Resources and Urban Planning in Singapore?
The Neysadurai Centre’s mission is to develop and apply tools that support sustainable urban planning and design. We recognize that various urban infrastructure sectors—water, energy, transportation, waste, pollution and natural systems—are complex individually and more so when tied together. We are using simulation tools to help engineers, urban planners and architects make informed decisions.
Asia is an exciting place to be in this field because of the rapid pace of urbanization and increases in living standards and consumption. These trends are both scary in their long-term implications and exciting in the opportunities they provide. To compensate, we will have to take green technologies and practices to the next level—we will need breakthrough reductions in water and energy use, waste production and pollution of natural systems.